Pushbutton actuator



Feb. 6, 1968 1 B. MOODY PUSHBUTTON ACTUATOR 2 Sheets-Sheet 1 Filed June10, 1965 INVENTOR James B. Moody BY M WQ ATTORNEY J. B. MOODY Feb. 6,1968 PUSHBUTTON ACTUATOR I 2 Sheets-Sheet -2 Filed June 10, 19653,367,2tlo E USHEUTTGN ACTUATGR James E. Moody, llndiana Township,Pittsburgh, Pa, assignor to Westinghouse Electric Corporation,Pittsburgh, Pm, a corporation of Pennsylvania Filed lune lit, 1965, Ser.No. 462,978 4 Claims. (Cl. 74-5h3) AELQTRAQT OF THE DECLQBSURE Moreparticularly, a plunger is slidably disposed in a supporting sleeve andincludes a resilient portion of reduced cross-section which movesthrough an opening in a transverse web in the sleeve. The latter portionof the plunger includes projecting tabs which retain the plunger inassembled relation with the sleeve. Additional openings may be providedin the web of the sleeve or in the plunger to act as spring seats forthe resetting springs disposed between the web and the plunger.

This invention relates to pushbutton structures and more particularly topushbutton actuators adapted for mounting on a supporting panel.

Pushbutton operators or actuators are commonly employed to actuateassociated electrical devices, such as switches, or to reset devices,such as thermostatic devices of the type which are included with motorstarters. For applications where the pushbutton operator is to bemounted on a supporting panel, it has been found that pushbuttonstructures of the type described which have been employed in the pasthave several disadvantages. For example, certain types of knownpushbutton structures do not readily lend themselves to mounting on anassociated supporting panel. Other types of known pushbutton operatorsdo not readily lend themselves to an oil-tight or fluid-tightconstruction or have the disadvantage that the pushbutton structurereduces the electrical insulating clearances between the supportingpanel and associated electrical appsratus which is disposed adjacent tothe supporting panel. It is, therefore, desirable to provide an improvedpushbutton structure which overcomes the above disadvantages and alsooffers several additional advantages.

It is an object of this invention to provide a new and improvedpushbutton actuator.

Another object of this invention is to provide an improved pushbuttonoperator which more readily lends itself to mounting on a supportingpanel.

A more specific object of this invention is to provide an improved meansfor maintaining a pushbutton actuator and an associated supporting meansin assembled relationship.

Other objects of the invention will, in part, be obvious and will, inpart, appear hereinafter.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description, taken inconjunction with the accompanying drawings, in which:

FIGURE 1 is an exploded view, in perspective, of a pushbutton operatorassembly embodying the principal features of the invention;

FIG. 2 is a view, partly in section and partly in elevation, of thestructure shown in FIG. 1 when assembled on a supporting panel;

FIG. 3 is a view, in section, of the structure shown in FIG. 2 takenalong the line IIIIII with the associated electrical apparatus indicatedin phantom;

FIG. 4 is a top plan view of a supporting sleeve which performs part ofthe structure shown in FIGS. 1 through 3;

ttes Patent Q 3,3612% Patented Feb. 6, 1968 ice FIG. 5 is an explodedview, in perspective, of an alternate construction of a pushbuttonactuator embodying the principal features of the invention.

FIG. 6 is an elevational view, partly in section and partly cut away ofthe structure shown in FIG. 5 when assembled on a supporting panel;

FIG. 7 is an elevational view, in section, of the structure shown inFIG. 6 taken along the line VIIVII; and

FIG. 8 is a diagrammatic view of a control system utilizing two of thepushbutton actuators shown in FIGS. 1 through 4.

Referring now to the drawings and to FIGS. 1 and 2 in particular, thereis illustrated a pushbutton operator or actuator assembly it] which isparticularly adapted for mounting on a supporting panel or housing wall42 of an associated electrical apparatus, such as a motor starter. Thesupporting panel 42 may be formed from a suitable material such as sheetsteel and in a typical application may comprise part of the door of anenclosure of the associated apparatus, such as the apparatus indicatedin phantom in FIG. 3, which is adjacent to and spaced from thesupporting panel 42. The pushbutton operator 10 may be operativelyconnected to the associated apparatus ltltl by an actuating member 92,as indicated in phantom in FIG. 3.

In general, the pushbutton operator 10 comprises a supporting sleeve orgenerally tubular member 20 and a plunger member or pushbutton member 30which i slidably disposed in the supporting sleeve 20, as best shown inFIGS. 2 and 3. As illustrated in FIG. 1, the supporting panel 42includes a generally circular opening 74 through which a portion of thesupporting sleeve 20 passes during the assembly of the pushbuttonoperator 10 on the supporting panel 42.

More specifically, the supporting sleeve 20 is preferably formed from anelectrically insulating material which is also resilient and which hassuitable mechanical wearing properties. One suitable material which hasbeen found to be particularly satisfactory is a thermoplastic materialsuch as an acrylonitrile butadiene styrene resin. The supporting sleeve24? includes a first portion 22 which has a larger outer periphery thanthe opening 74 in the associated supporting panel 42 and a secondportion 24 which has an outer periphery smaller than the opening 74 andwhich passes through the opening '74 when the supporting sleeve 2% isassembled with the supporting panel 42, as shown in FIGS. 2 and 3. Asshown in FIG. 1, a shoulder portion 22A is formed on the outer peripheryof the supporting sleeve 20 where the first portion 22 joins or meetsthe second portion 24. When the supporting sleeve 20 is assembled withthe supporting panel 42 as shown in FIG. 2, the shoulder portion 22A maybear directly against one side of the supporting panel 42 around theopening 74 or gasket member 72 may be interposed between the shoulderportion 22A and the supporting panel 42 to substantially prevent theentrance of oil or other fluids. In order to retain the supportingsleeve 2!) in assembled relationship with the supporting panel 42, aself-locking, bowed, retaining, snap ring 62 may be assembled over thesecond portion 24 of the supporting sleeve 20 and pressed against theother side of the supporting panel 42 opposite the shoulder portion 22Auntil the retaining ring 62 snaps into a groove 22B provided on theouter surface of the second portion 24 of the supporting sleeve 20. Inorder to properly position the supporting sleeve 20 with respect to theopening 74- provided in the supporting panel 42, a projecting portion 23may be provided inside the groove 223 on the outer periphery of thesecond portion 24 of the supporting sleeve 2%. The projecting portion 23projects into a corresponding guiding recess 74A which is disposed at apredetermined point around the periphery of the opening 74, as bestshown in FIG. 1.

The supporting sleeve 29 is provided with a transversely extending webportion 29 having a generally rectangular opening 28 therein, as bestshown in FIGS. 2 and 4. As illustrated, the supporting sleeve alsoincludes a transversely extending recess across the bottom of the secondportion 24 of the supporting sleeve 20 to thereby form a pair ofshoulder portions 21 at the opposite sides of the opening 28, as bestshown in FIG. 1. As will be explained in detail hereinafter, the webportion 29 of the supporting sleeve 20 assists in guiding the axialmovement of the plunger member within the supporting sleeve 20 and alsoprevents rotation of the plunger member 39 in place during the operationof the pushbutton operator It).

As mentioned previously, the plunger member 30 is slidably disposed inthe supporting sleeve 20 and is preferably formed from an electricallyinsulating material which is resilient and which has suitable mechanicalwearing properties, such as the material previously mentioned inconnection with the supporting sleeve 20. The plunger member 30comprises an upper portion which is generally circular in configurationand which substantially fills the opening inside the first portion 22 ofthe supporting sleeve 20 and a second portion which is generallyrectangular in configuration and which substantially fills the generallyrectangular opening 28 in the web portion 29 of the supporting sleeve20. Where desired, a recess as may be provided around the outerperiphery of the upper portion 36 of the plunger member St) in which anO-ring gasket may be disposed to substantially prevent the entrance ofoil or other fluids into the space or clearance provided between theouter periphery of the upper portion 36 of the plunger member 3% and theinner surface of the first portion 22 of the supporting sleeve 2%. TheO-ring gasket 44 is preferably formed from a suitable resilient,electrically insulating material where provided.

It is to be noted that the cross-section of the upper portion 36 of theplunger member 30 is larger than the size of the opening 28 through theweb portion 29 of the supporting sleeve 20 and also greater than thecrosssection of the substantially rectangular lower portion 34 of theplunger member 36 to define a shoulder portion 36 where the upperportion 35 meets the lower portion 34 of the plunger member 32, as bestshown in FIGS. 2 and 3. In the normal operating position of the plungermember 30 as shown in FIGS. 2 and 3, the shoulder portion 36 is axiallyspaced from the upper surface of the web portion 29.

In order to releasably retain the plunger member 30 in assembledrelationship with the supporting sleeve 20, the projecting tab portions38 are provided on the opposite sides of the lower portion 34 of theplunger member 30 to engage the shoulder portion 21 provided at thebottom of the web portion 29 of the supporting sleeve 20 when theplunger member 36 is assembled with the supporting sleeve 20. In orderto permit assembly of the plunger member 30 with the supporting sleeve20, one or more axially extending slots 35 are provided in the lowerportion 34 of the plunger member 30, as best shown in FIG. 2, to permitthe outer portions or prongs of the lower portion 34 of the plungermember 3d to deflect during the assembly of the plunger member 30 withthe supporting sleeve 20 and to permit the lower portion 34 of theplunger member 30 to pass through the opening 28 until the outerportions of the lower portion 34 of the plunger member 30 spring to theposition shown in FIG. 2 with the projecting portions 38 engaging thebottom of the web portion 29. As mentioned previously, the plungermember 30 is preferably formed from a resilient material to permit thedeflection of the projecting portion 38 during the manual assembly ofthe plunger member 30 with the supporting sleeve 20 or the removal ofthe plunger member 39 from the supporting sleeve 20.

In order to receive one end of an actuating member, such as theactuating member 92 of an associated apparatus, such as the apparatus160 indicated in phantom in MG. 3, the lower portion 34- of the plungermember 3% may be provided with a vertically extending opening 3'? intowhich one end of the actuating member 92 may project when the pushbuttonoperator 10 is assembled on the associated supporting panel 42. Durinthe operation of the pushbutton operator 18, the plunger member 30 whichis siidably disposed within the supporting sleeve 23 may be manuallyactuated or pushed in a downward direc ion, as viewed in FIGS. 2 and 3,to also actuate or push the actuating member 92 in a downward direction.Where the actuating member 92 is normally reset by a spring meansincluded in the apparatus 100, the plunger member 30 will also be resetby the upward resetting movement of the actuating member 92 to thenormal position shown in FIGS. 2 and 3. Where required, a resettingspring means may be included with the pushbutton operator assembly it),as best shown in FIGS. 1 and 3. this instance, the supporting sleeve 20may be provided with a pair of vertically extending openings 26 whichact as spring seats for a pair of associated resetting springs 32, asbest shown in FIGS. 3 and 4. The compression springs operate to bias theupper portion 32 of the plunger member 38 away from the web portion 29of the supporting sleeve 2% after the plunger member 30 has beenmanually actuated in a downward direction to thereby reset the plungermember to its normal position shown in FIGS. 2 and 3.

in certain applications, the opening 37 in the plunger 3% may beinternally threaded or employed to receive a fastening means, such as a.bolt or screw, for securing an extension member to the lower end of theplunger 30 where required.

Where it is desired to support an associated apparatus, such as aswitch, on the supporting sleeve 20 of the pushbutton operator assembly1'3, the openings 26 may be shifted by a p 'edetermined angie from thepositions shown in full in FIG. 4 to the positions indicated in phantomat in FIG. 4 and a pair 0t additional openings 27 may be provded in thesupporting sleeve 20 to receive suitable fastening means such as boltsor screws. In the latter arrangement, the openings 27 may be internallythreaded to engage the associated fastening means.

it is to be noted that, in the absence of the resetting springs 32 in aparticular application, the upper surface of the web portion 29 of thesupporting seeve 20 may act as a stop means during the movement of theplunger member 36 into the supporting sleeve 26 when the shoulderportion 36A of the plunger member 30 engages the upper surface of theweb portion 29.

Referring now to FIGS. 5 to 7, there is illustrated an alternatepushbutton operator assembly ltii) which in general is similar to thepushbutton operator assembly 10 previously described except that thesupporting sleeve 120 of the pushbutton operator assembly is alsoretained in assembled relationship with the associated supporting panel42 by projecting tab portions 125, similarly to the projecting tabportion 38 of. the plunger member 30 of the pushbutton operator assembly10.

More specifically, the pushbutton operator assembly 100 includes asupporting sleeve or generally tubular member 129 and a plunger member130 which is slidably disposed in the supporting sleeve similarly to thepushbutton operator assembly 10. The supporting sleeve 12% includes anupper portion 122 which is generally circular in configuration and whichhas a larger outer periphery than the opening 74 in the associatedsupporting panel 42 and a second portion 124 which has a smaller outerperiphery than the first portion 122 of the supporting sleeve 120. Thesupporting sleeve 120 is preferably formed from an electricallyinsulating material which is resilient and which has suitable mechanicalwearing properties, such as the material previously disclosed inconnection with the supporting sleeve Zll of the pushbutton operatorassembly 19.

In order to releasably retain the supporting sleeve 120 in assembledrelationship with the associated supporting panel 4-2;, the second orlower portion 124 of the supporting sleeve 129 includes a plurality ofprojecting tab portions 125 which project outwardly beyond the peripheryof the opening in the supporting panel 42 when the supporting sleeve12!) is assembled with the supporting panel 42 to engage one side of thesupporting panel 42. It is to be noted that when the supporting sleeve128 is assembled with the supporting panel 4-2, the supporting panel 4-2is disposed between a shoulder portion 122A which results where theupper portion 122 of the supporting sleeve 12d meets the lower portion124 and the projecting tab portions 125 which are axially spaced fromthe shoulder portion 122A by a predetermined distance which issubstantially equal to the thickness of the supporting panel 42. Inorder to permit the projecting tab portions 125 to deflect during theassembly of the supporting sleeve 120, with the supporting panel 42-, aslot 27 may be provided adjacent to each of the projecting tab portions,as best shown in FIG. 5, to permit the projecting tab portions 225 todeflect inwardly away from the edge of the opening 74 provided in thesupporting panel 2.

Similarly to the supporting sleeve Zll, the supporting sleeve 1%includes a transversely extending web portion 129 having a generallyrectangular opening 128 provided therein which similarly assists inguiding the reciprocating movement of the plunger member 13% within thesupporting sleeve Pt) and which also prevents rotation of the plungermember 1345 in place. As illustrated, the transversely extending webportion 129 includes a pair of upwardly extending projecting portions1223 and 122C on the opposite sides of the opening 128 which may beemployed as spring seats where resetting springs are included as part ofthe pushbutton operator assembly Iltltl.

Similarly to the plunger member 39, the plunger memher 130 of thepushbutton operator assembly includes a generally circular upper portion132 and a generally rectangular lower portion 13-45. The lower portion136 includes a pair of projecting tab portions 133 at the lower endthereof and may include one or more vertically extending slots 35 topermit the deflection of the projecting tab portions 133 during theassembly or removal of the plunger member 139 into or out of thesupporting sleeve 1%. The lower portion 134 may also include avertically extending opening 137 which is adapted to receive one end ofan actuating member of an associated app ratus similarly to the opening37 provided in the plunger member 39 of the pushbutton operator assembly16' previously described. Where required for resetting springs such as aresetting spring 182 shown in FIGS. 5 and 7, the upper portion 132 ofthe plunger member 139 may include one or more vertically extendingopenings 126 which are adapted to receive one of the associatedresetting springs 182 and function as spring seats. As shown in PEG. 7,one end of each of the resetting springs 182 is positioned on one of thespring seat portions 122A or 1223 and the other end of the resettinspring is disposed inside one of the openings 126 provided in thisinstance in the upper portion 132 of the plunger member 13%. It is to benoted that the projecting tab portions 13% provided on the plungermember 13s engage the bottom surface of the web portion 129 adjacent tothe opening 123 provided in the web portion 129.

The operation of the pushbutton operator assembly 1% is similar to thatof the pushbutton operator assembly ltl previously described. Theplunger member 136 may be manually actuated in a downward direction toactuate an associated apparatus which is operatively connected to thepushbutton operator assembly 1% in similar fashion to the pushbuttonoperator assembly it) previously described. As previously mentioned inconnection with the pushbutton operator assembly llll, the resilience ofthe material from which the plunger member is formed permits thedeflection of the lower portions of the plunger member 13 5 during theassembly or removal of the plunger member 13s with respect to theassociated supporting sleeve 1229.

Referring now to FIG. 8, there is illustrated diagrammatically a typicalapplication in which two of the pushbutton operator assemblies fill maybe employed. As illustrated, an electric motor 25% is arranged to beenergized from a three-phase source of alternating current electricpower, as indicated by the terminals S1, S2 and S3, through theseparable contacts 212, 214 and are, respectively, of a contactor 2110.in order to electrically connect the motor 2% to the terminals S1, S2and S3, the operating coil or solenoid 222 of the contactor 21b isenergized by actuatin a normally open ON pushbutton to the closedposition to thereby form a series circuit which extends from theterminal Sl, through the normally closed contacts 226 and 23d of theoverload relays 229 and 2W, respectively, through the operating coil oithe contactor Zltl, through the OFF pushbutton which is normally closedand the momentarily closed ON pushbutton 242 to the terminal S2. Thecontacts 212, 21 and 21d of the contactor Zlll will then be actuated tothe closed position to thereby energize the motor along with a contact218 which will close and form a holding circuit around the ON pushbutton2 32 which is normally a momentary pushbutton. In order to protect themotor 25% from certain overload conditions, the heater elements 224 and234 of the overload relays and respectively, are electrically connectedin series with the contacts H2 and are, respectively, of the contactorZltl between the motor 23% and the source terminals S1 and 33,respectively. When certain overload conditions result in the motor 259,the bimetallic elem nts Bit and B2 of the overload relays 2236 or 23%,respectively, are actuated by the associated heater elements 224; and 23respectively, to cause the normally closed contacts 226 or 235,respectively, to open and deenergize the operating coil 222 of thecontactor 219 to open the contacts 112, Zl l and 216 and to therebyelectrically disconnect the motor from the source terminals Sl, S2 andS3.

In order to reset the bimetallic elements B1 or B2 of the overloadrelays 220 or 23% respectively, a pushbu'tton operator assembly it maybe provided adjacent to each bimetallic element to reset the bimetallicelements B1 or B2 after the bimetallic elements have cooled followingthe electrical deenergization of the motor 25% by the contactor 21th, asjust explained. The motor 254) may also be dcencrgized in a conventionalmanner by OFF pushbutton 244 which may be actuated to an positionmanually to deenergize the operating coil the contactor in a typicalmotor control system. It is to be noted that the pushbutton switches 242and may include a pushbutton actuator, such as the pushbutton actuatorsit} and rec previously disclosed. In the latter construction, thepushbutton operators it) or ltltl would actuate conventional separablecontacts of any suitable type.

It is to be understood that a pushbutton operator assembiy, asdisclosed, may be employed to reset electrical apparatus as justdescribed in a typical application or may be employed to actuate anassociated electrical apparatus, such as a switch, which is operativelyconnected to the pushbutton operator assembly.

The apparatus embodying the teachings of this invention has severaladvantages. For example, a pushbutton operator assembly as disclosed maybe assembled in a simpler manner and in certain applications without theuse of special tools. In addition, the pushbutton operator assembly, asdisclosed, which is formed preferably of electrical insulating materialprovides increased electrical insulating clearances between thesupporting panel on which the pushbutton operator assembly is disposedand the associated apparatus which is normally disposed adjacent to andspaced from the supporting panel. Finally, a pushbutton operatorassembly as disclosed readily lends itself to an oil-tight or fiuidtightconstruction.

Since numerous changes may be made in the above described apparatus anddifferent embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all the mattercontained in the foregoing description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. A pushbutton actuator comprising a supporting sleeve having atransverse web with a central opening therein which extends axiallytherethrough, a plunger member slidably disposed in the sleeve, saidplunger member including a first portion which has a cross-sectionlarger than said opening and which is disposed on one side of the weband a second portion which has a cross-section smaller than said openingand which extends through said opening, the second portion of theplunger member including one or more projecting tabs which engage theother side of the web to releasably retain the plunger member inassembled relationship with the sleeve, the web of said sleeve includingone or more additional openings laterally spaced from said centralopening and extending axially only partially therethrough, and springmeans disposed between the first portion of the plunger member and theweb to extend into each of the additional openings and to bias theplunger member away from the web.

2. A pushbutton actuator adapted for mounting on a supporting wallcomprising a supporting sleeve having a transverse web with a centralopening extending axially therethrough, a pushbutton member which isslidably disposed in the sleeve, said sleeve having a first portionwhich has a periphery larger than the opening and a second portion whichhas a periphery smaller than the opening to define a shoulder at theline of junction between said first and second portions which is adaptedto bear against one side of the supporting wall, the second portion ofthe sleeve including one or more projecting portions on the outerperiphery spaced from the shoulder and adapted to engage the other sideof the supporting wall and to releasably retain the sleeve on the Wall,said pushbutton member including a first portion having a cross-sectionlarger than the opening through the web disposed on one side of the weband a second slotted portion having a cross-section smaller than theopening and extending through the opening of the web, the slottedportion of the pushbutton including one or more projecting portionsadapted to engage the other side of the web and to releasably retain thepushbutton member in assembled relation with the sleeve, the web or"said sleeve including one or more additional openings laterally spacedfrom said control opening and extending axially only partiallytherethrough, and spring means disposed inside the sleeve between theweb and the first portion of the pushbutton member to extend into eachof the additional openings and to bias the pushbutton member away fromthe Web.

3. A pushbutton operator comprising a supporting sleeve having atransverse web with a substantially rectangular opening therein, aplunger member slidably disposed in the sleeve, said plunger memberincluding a first portion which has a cross-section larger than that ofthe opening in the web and which is disposed on one side of the web anda second slotted portion which has a substantially rectangularcross-section smaller than that of the opening in the web and whichsubstantially fills the opening, the second portion of the plungermember being formed of a resilient material and extending through theopening in the web, one or more projecting tabs integrally formed withthe second portion of the plunger member to engage the other side of theweb and to releasably retain the plunger member in the sleeve, andspring means disposed inside the sleeve between the web and the firstportion of the plunger member to bias the first portion of the plungermember away from the web, the second portion of the plunger memberincluding an axially extending opening only at the end away from thefirst portion which is adapted to receive an actuating member of anassociated apparatus.

4. A pushbutton operator comprising a supporting sleeve having atransverse web with a substantially rectangular opening therein, and aplunger member slidably disposed in the sleeve, said plunger memberincluding a first portion which has a cross-section larger than that ofthe opening in the web and which is disposed on one side of the web anda second slotted portion which has a substantially rectangularcross-section smaller than that of the opening in the web and whichsubstantially fills the opening, the second portion of the plungermember being formed of a resilient material and extending through theopening in the Web, and one or more projecting tabs integrally formedwith the second portion of the plunger member to engage the other sideof the Web and to releasably retain the plunger member in the sleeve,the first portion of the plunger member including one or more openingsextending axially from adjacent the second portion of the plunger memberthrough part of the first portion and spring means disposed between theweb and the first portion of the plunger member to extend into each ofthe latter openings and to bias the first portion of the plunger memberaway from the web.

References Cited UNITED STATES PATENTS 3,047,700 7/1962 Bailey.3,099,771 7/1963 Matiyak et al. 3,169,410 2/1965 Armandroff 745033,172,985 3/1965 De Smidt.

3,212,351 10/1965 Ruckriegel et al. 74-503 3,234,566 2/1966 Rupp 74-503FOREIGN PATENTS Ad. 58,102 9/1953 France.

FRED C. MATTERN, 111., Primary Examiner.

W. S. RATLIFF, Assistant Examiner.

